The present invention relates to a signal processing technique concerning a singing voice.
In recent years, it is a common practice that a person who is not a professional singer captures his/her own singing scene as a moving image and posts the moving image on a moving image posting site or the like.
[Patent Document 1] JP 2007-240564 A
[Patent Document 2] JP 2013-137520 A
[Patent Document 3] JP 2000-003200 A
It is often the case that posters on the moving image post their moving images with the same feeling as when singing karaoke songs. There are some posters, among the posters on the moving image, who desire to modify their singing voice to a singing voice which gives listeners the impression of singing well and post the modified moving images. However, there has heretofore been no technique serving such a need.
Examples of a signal processing technique concerning a singing voice include techniques disclosed in Patent Document 1 and Patent Document 2. The technique disclosed in Patent Document 1 is a technique which imparts a motion to a pitch according to a predetermined pitch model so as for the pitch to change continuously in note switching portions. On the other hand, the technique disclosed in Patent Document 2 is a technique which, by providing each note with control information defines a change in pitch, controls the change in pitch from a sound production start time point until reaching a target pitch according to the control information. However, the techniques disclosed in the individual documents of Patent Document 1 and Patent Document 2 are both a technique for uniquely synthesizing natural singing voices according to a singing synthetic score or the like, and neither of them is a technique which controls for each singer the skill impression of the singing voices of persons different in personality. There is a problem that supposing that a singing voice is attempted to be modified by the technique disclosed in Patent Document 1 or Patent Document 2, the singing voice is modified so as to have a pitch motion (pitch change) shown in the predetermined pitch model (control information), as a result of which all the singing voices, no matter how they are, become of the same pitch motion (pitch change), and the personalities of the singers are completely eliminated.
An example of a technique which changes an impression of a singing voice is disclosed in Patent Document 3. Patent Document 3 discloses a technique in which a male voice is modified to a pitch conversion and then added with aspirated noise according to format of the converted voice, thus being converted into a female voice natural in hearing sense. However, the technique disclosed in Patent Document 3 cannot change an impression of skill of singing.